1. Field of the Invention
The present invention relates to an optical device wafer processing method for grinding an optical device wafer to reduce the thickness thereof to a predetermined thickness, wherein a plurality of crossing streets are formed on the front side of a sapphire substrate to thereby partition a plurality of regions where a plurality of optical devices are correspondingly formed, each optical device being formed from a gallium nitride compound semiconductor, for example.
2. Description of the Related Art
An optical device wafer has a configuration such that a plurality of crossing division lines called streets are formed on the front side of a sapphire substrate to thereby partition a plurality of regions where a plurality of optical devices are correspondingly formed, each optical device being formed from a gallium nitride compound semiconductor. The optical device wafer is divided along the streets to obtain the individual optical devices such as light emitting diodes, which are widely used in electrical equipment (see Japanese Patent Laid-Open No. Hei 10-305420, for example).
The optical device wafer is formed by growing a semiconductor layer of a gallium nitride compound or the like constituting the optical devices on the front side of a substrate. Accordingly, sapphire effective for the growth of the semiconductor layer is used as the substrate. To improve the luminance, the back side of the sapphire substrate constituting the optical device wafer is ground to reduce the thickness of the wafer to about 100 μm.